Preparation method of high-strength, high-plasticity, high-modulus and low-temperature-resistant aluminum-based composite material

Abstract

The invention belongs to the field of composite materials, and particularly relates to a preparation method of a high-strength, high-plasticity, high-modulus and low-temperature-resistant aluminum-based composite material. The method comprises the following steps of (1) surface treatment and refinement of an aluminum matrix material and a powder material, (2) cold pressing of a powder mixture and compression molding of powder, (3) liquid-solid reaction at 650-850 DEG C in an argon atmosphere to prepare an Al3BC reinforced composite material, and (4) extrusion of the obtained modified Al3BC / aluminum-magnesium composite material to obtain the composite material. According to the preparation method, materials are compounded through compression molding, liquid-solid reaction and other methods, dislocation movement can be inhibited through dissolved Mg atoms, more dislocations can be stored in an Al matrix at low temperature, the mechanical property of the composite material is improved, meanwhile, Al3BC particles generated through in-situ reaction are directly generated in the matrix, and the mechanical property of the composite material is improved. The aluminum-based composite material has the advantages of being smaller in particle size, more uniform in distribution and more excellent in particle and matrix combination, the aluminum-based composite material can retain good ductility at low temperature, and therefore the high-strength, high-plasticity and high-modulus aluminum-based composite material with higher mechanical performance and good ductility at the low temperature is obtained. The purposes of high strength, high plasticity and high modulus at low temperature are achieved, and better integration is obtained.

Description

Technical Field

[0001] The invention belongs to the field of low-temperature metal materials, and in particular relates to a method for preparing a high-strength, high-plasticity, high-modulus, low-temperature-resistant aluminum-based composite material. Background Art

[0002] Aluminum and its alloys have a wide range of applications in the fields of structural materials and functional materials due to their low density, high specific strength, good corrosion resistance, and good electrical conductivity. With the rapid development of modern science and technology, higher requirements are placed on the comprehensive performance of materials. For example, the aerospace field requires lighter and stronger materials, among which precision components have more stringent requirements on the modulus and wear resistance of materials. Low-temperature resistant materials can maintain their excellent mechanical properties, such as strength, toughness and stiffness, in extremely low temperature environments, prevent equipment icing and material embrittlement caused by low temperatures, reduce the risk of failure of spacecraft, ensure its stable operation in space, and improve its reliability and safety in complex space environments. Usually, the elastic modulus of aluminum alloys is low (about 70GPa), and a single aluminum alloy can no longer meet so many requirements. The research and development and application of new materials is the general trend, and adding a high-modulus reinforcement phase is an effective way to improve the modulus of aluminum alloys. Compared with common ceramic particle reinforcement phases, such as TiB2, TiC, SiC, Al2O3, etc., Al3BC has a lower density (2.85g / cm 3 ), which has a density similar to that of aluminum, is easier to disperse when added to an aluminum matrix. At the same time, its elastic modulus reaches 326GPa, which significantly improves the modulus of the aluminum matrix. At present, the research on the microstructure and properties of aluminum-based composite materials is mainly focused on room temperature, and there are relatively few studies on mechanical properties below room temperature to liquid nitrogen temperature.

[0003] At present, some studies have formed Al3BC particle-reinforced aluminum-based composites through in-situ synthesis methods. The patent "Coated composite particle reinforced high-strength and high-modulus aluminum-based composite materials and preparation methods, Liu Xiangfa, Han Mengxia, Liu Guiliang, Gao Tong" reported a method for preparing Al4C3@Al3BC coated particle-reinforced Al composites through in-situ synthesis technology, but the Al3BC particle size is relatively large, ranging from 500nm to 15μm. The larger size of the reinforcing phase will induce cracks in the aluminum matrix, etc., reducing the mechanical properties of the material.

[0004] The patent "Method for preparing adjustable TiB2 in-situ reinforced aluminum-based composite materials, Fan Yuhu, Yu Shenwei, Wang Chenghui, Wang Huimei, Wang Yong, Cao Dong" reports an adjustable TiB2 in-situ reinforced aluminum-based composite material made by melting aluminum-boron alloy and aluminum-titanium alloy and adding them to an aluminum alloy matrix, but the AlB2 is large in size and brittle, which is also not conducive to the performance of the material properties.

[0005] In addition, the presence of large particles and particle aggregation areas may cause cracking or debonding of the matrix, becoming a potential source of cracks. This will lead to premature failure of AMCs, while most aluminum alloys increase their strength and ductility simultaneously at low temperatures. Compared with particles generated non-in situ, in-situ particles generated directly in the matrix have a smaller diameter, more uniform distribution, and usually have a better bonding interface with the matrix. These advantages are conducive to improving the room temperature properties of composites and can be maintained in cryogenic environments. Therefore, in-situ particle-reinforced aluminum alloy composites have the potential to maintain sufficient ductility at low temperatures. Therefore, the development of a high-strength, high-plastic, and high-modulus aluminum-based composite material at low temperatures will promote the development of aerospace material technology, improve the adaptability and durability of related aerospace components, and promote the development of related industries. Summary of the invention

[0006] The purpose of the present invention is to provide a method for preparing a high-strength, high-plasticity, high-modulus, low-temperature-resistant aluminum-based composite material.

[0007] The technical solution to achieve the purpose of the present invention is:

[0008] Mg atoms have high solubility and good solid solution strengthening effect in the Al matrix. By adding the element Mg, the dissolved Mg atoms can inhibit dislocation movement, so that the Al matrix can store more dislocations at low temperatures, thereby improving the low-temperature mechanical properties of the material. At the same time, Al3BC reinforcing particles are generated through in-situ reactions, and their microstructure is more uniform and has better bonding with the matrix interface, which can reduce stress concentration to a certain extent and avoid the generation of cracks at low temperatures, so that the material has improved mechanical properties at low temperatures while maintaining good ductility. DETAILED DESCRIPTION

[0009] The present invention is described in further detail below.

[0010] The invention discloses a method for preparing a high-strength, high-plasticity, high-modulus, low-temperature-resistant aluminum-based composite material. By adding Mg elements, Mg atoms have high solubility in an Al matrix and good solid solution strengthening effect, and the Al-Mg alloy has excellent low-temperature strength and ductility. The dissolved Mg atoms can inhibit dislocation movement, and the Al matrix stores more dislocations at low temperatures, thereby improving the mechanical properties of the composite material. At the same time, Al3BC particles generated by in-situ reaction are directly generated in the matrix, and have the advantages of smaller particle size, more uniform distribution, and better combination of particles and matrix, so that the aluminum-based composite material can retain good ductility at low temperatures, thereby obtaining a high-strength, high-plasticity, high-modulus aluminum-based composite material with higher mechanical properties and good ductility at low temperatures.

[0011] The preparation of high-strength, high-plasticity and high-modulus aluminum-based composite materials comprises the following steps:

[0012] Step (1): industrial pure aluminum powder (purity 99.7wt%, particle size 1μm to 15μm), Al-50Mg alloy powder (particle size 20μm to 50μm, magnesium content 49.5% to 50.5%), aluminum-aluminum boron carbon alloy powder (purity not less than 98.5wt%, particle size 1μm to 15μm, aluminum-aluminum boron carbon alloy powder is rich in flaky nano-Al3BC particles, Al3BC content is 30%).

[0013] Prepare the required materials according to the following mass percentages: 56.70wt% to 80.75wt% of industrial pure aluminum powder, 0.55wt% to 11.8wt% of Al-50Mg alloy powder, and 16.5wt% to 35wt% of aluminum-aluminum boron carbon alloy powder; and achieve composite materials with different proportions of magnesium by changing the addition amount of Al-50Mg powder.

[0014] Step (2): ball milling, the raw material powders are evenly mixed and ball milled in an argon atmosphere for 2h to 6h, the ball milling speed is 100r / min to 240r / min, and then the powder mixture is cold pressed in a cold isostatic press, and then the powder is pressed into shape with a hydraulic press.

[0015] Step (3): Under an argon atmosphere, a liquid-solid reaction was carried out at 650°C-850°C for 0.5h-2h to prepare Al3BC reinforced Al-xMg (x=1, 3, 5wt%) composite materials.

[0016] Step (4): extrusion deformation, extruding the obtained modified Al3BC / aluminum-magnesium composite material, extruding the composite material at 400°C to 500°C with an extrusion ratio of 9 / 1 to 20 / 1, to obtain a composite rod with a diameter of about 20 mm to 30 mm.

[0017] Example 1

[0018] Step (1): 76.09wt% industrial pure aluminum powder, 3.6wt% Al-50Mg alloy powder, and 20.31wt% aluminum-aluminum boron carbon alloy powder. Among them, industrial pure aluminum powder (purity 99.7wt%, particle size 1μm-15μm), Al-50Mg alloy powder (particle size 20μm-50μm, magnesium content 49.5%-50.5%), aluminum-aluminum boron carbon alloy powder (particle size ≤50nm, purity>99.9%, aluminum-aluminum boron carbon alloy powder is rich in flaky nano-Al3BC particles, Al3BC content is 30%)

[0019] Step (2): ball milling: the raw material powders are evenly mixed and ball milled in an argon atmosphere for 2 hours at a ball milling speed of 150 r / min. The powder mixture is then cold pressed in a cold isostatic press, and then the powder is pressed into shape using a hydraulic press.

[0020] Step (3): Al3BC was subjected to liquid-solid reaction at 680°C for 0.5 h in an argon atmosphere to prepare Al3BC nanoparticle-reinforced Al-1Mg-based composite materials.

[0021] Step (4): extrusion deformation, extruding the obtained modified Al3BC / aluminum-magnesium composite material, extruding the composite material at 400°C with an extrusion ratio of 9:1 to obtain a composite rod with a diameter of about 30 mm.

[0022] Step (5): Through the tensile test, at room temperature, the yield strength of the composite material is 368 MPa, and the ultimate tensile strength is 515 MPa. At low temperature of liquid nitrogen, the yield strength of the composite material is 416 MPa, and the ultimate tensile strength is 608 MPa.

[0023] Example 2

[0024] Step (1): 68.89wt% industrial pure aluminum powder, 10.8wt% Al-50Mg alloy powder, and 20.31wt% aluminum-aluminum boron carbon alloy powder. Among them, industrial pure aluminum powder (purity 99.7wt%, particle size 1μm-15μm), Al-50Mg alloy powder (particle size 20μm-50μm, magnesium content 49.5%-50.5%), aluminum-aluminum boron carbon alloy powder (particle size ≤50nm, purity>99.9%, aluminum-aluminum boron carbon alloy powder is rich in flaky nano-Al3BC particles, Al3BC content is 30%)

[0025] Step (2): ball milling: the raw material powders are evenly mixed and ball milled in an argon atmosphere for 3 hours at a ball milling speed of 180 r / min. The powder mixture is then cold pressed in a cold isostatic press, and then the powder is pressed into shape using a hydraulic press.

[0026] Step (3): Al3BC was subjected to liquid-solid reaction at 700°C for 2 h in an argon atmosphere to prepare Al3BC nanoparticle-reinforced Al-3Mg-based composite materials.

[0027] Step (4): extrusion deformation, extruding the obtained modified Al3BC / aluminum-magnesium composite material, extruding the composite material at 450°C with an extrusion ratio of 15:1, and obtaining a composite rod with a diameter of about 25 mm.

[0028] Step (5): Through the tensile test, at room temperature, the yield strength of the composite material is 397 MPa, and the ultimate tensile strength is 562 MPa. Under the low temperature of liquid nitrogen, the yield strength of the composite material is 453 MPa, and the ultimate tensile strength is 633 MPa.

[0029] Example 3

[0030] Step (1): 61.69wt% industrial pure aluminum powder, 18wt% Al-50Mg alloy powder, and 20.31wt% aluminum-aluminum boron carbon alloy powder. Among them, industrial pure aluminum powder (purity 99.7wt%, particle size 1μm-15μm), Al-50Mg alloy powder (particle size 20μm-50μm, magnesium content 49.5%-50.5%), aluminum-aluminum boron carbon alloy powder (particle size ≤50nm, purity>99.9%, aluminum-aluminum boron carbon alloy powder is rich in flaky nano-Al3BC particles, Al3BC content is 30%)

[0031] Step (2): ball milling: the raw material powders are evenly mixed and ball milled in an argon atmosphere for 5 hours at a ball milling speed of 220 r / min. The powder mixture is then cold pressed in a cold isostatic press, and then the powder is pressed into shape using a hydraulic press.

[0032] Step (3): Al3BC was subjected to liquid-solid reaction at 800°C for 3 hours under argon atmosphere to prepare Al3BC nanoparticle reinforced Al-5Mg based composite material.

[0033] Step (4): extrusion deformation, extruding the obtained modified Al3BC / aluminum-magnesium composite material, extruding the composite material at 450°C with an extrusion ratio of 20:1, and obtaining a composite rod with a diameter of about 20 mm.

[0034] Step (5): Through the tensile test, at room temperature, the yield strength of the composite material is 430 MPa, and the ultimate tensile strength is 578 MPa. Under the low temperature of liquid nitrogen, the yield strength of the composite material is 619 MPa, and the ultimate tensile strength is 709 MPa.

Claims

1. A method for preparing a high-strength, high-modulus, low-temperature-resistant aluminum-based composite material, characterized in that: The steps include: Step (1): Preparation of raw powder: The raw powder is industrial pure aluminum powder, Al-50Mg alloy powder and aluminum-aluminum boron carbon alloy powder rich in flaky nano-Al3BC particles; Step (2): ball milling and pressing; Step (3): performing a liquid-solid reaction under an inert atmosphere to prepare an Al3BC-reinforced Al-xMg-based composite material; Step (4): performing hot extrusion deformation at an extrusion ratio of 9 / 1 to 20 / 1 to obtain a high-strength, high-modulus, low-temperature-resistant aluminum-based composite material.

2. The method according to claim 1, characterized in that In step (3), the value of x in the Al-xMg-based composite material is 0.5 to 5.

5.

3. The method according to claim 1, characterized in that In step (1), the purity of the industrial pure aluminum powder is not less than 99.7wt%, and the particle size is 1μm to 15μm; the purity of the Al-50Mg alloy powder is not less than 98.5wt%, and the particle size is 20μm to 50μm; the purity of the aluminum-aluminum boron carbon alloy powder is not less than 98.5wt%, and the particle size is 1μm to 15μm, wherein the Al3BC content is 30wt%.

4. The method according to claim 3, characterized in that Industrial pure aluminum powder 56.70wt% ~ 80.75wt%, Al-50Mg alloy powder 0.55wt% ~ 11.8wt%, aluminum-aluminum boron carbon alloy powder 16.5wt% ~ 35wt%.

5. The method according to claim 1, characterized in that The step (2) of ball milling specifically comprises: mixing the raw material powders uniformly and ball milling them in an argon atmosphere for 2 h to 6 h, with a ball milling speed of 100 r / min to 240 r / min.

6. The method according to claim 1, characterized in that The pressing and molding in step (2) is specifically as follows: cold pressing the ball-milled powder mixture in a cold isostatic press, and then pressing the powder into a shape using a hydraulic press.

7. The method according to claim 1, characterized in that The liquid-solid reaction in step (3) is specifically as follows: in an argon atmosphere, liquid-solid reaction is carried out at 650° C.-850° C. for 0.5 h to 2 h.

8. The method according to claim 7, characterized in that The hot extrusion deformation in step (4) is specifically as follows: the Al3BC reinforced Al-xMg based composite material obtained by the liquid-solid reaction is extruded at 400°C to 500°C with an extrusion ratio of 9 / 1 to 20 / 1 to obtain a rod with a diameter of 20mm to 30mm.

9. A high-strength, high-modulus, low-temperature-resistant aluminum-based composite material, characterized in that: The method is prepared by any one of claims 1 to 8.

10. Use of the material according to claim 9, characterized in that: For use in aerospace applications at temperatures below room temperature to liquid nitrogen.